Clutch operating mechanism



March 28, 1944. c. M. EASON CLUTCH OPERATING MECHANISM Original FiledSept. 4, 1940 5 Sheets-Sheet l CZarerzcefiiasm.

March 28, 1944. c, EASQN CLUTCH OPERATING MECHANISM Original Filed Sept.4, 1940 3 Sheets-Sheet 2 March 28, 1944. c. M. EASON CLUTCH OPERATINGMECHANISM Original Filed Sept. 4, 1940 3 Sheets-Sheet 3 77 L? d5 '27 l?I I fnvenior" Clcv'encejf Ewan 0 012 M am I fi Patented Mar. 28, 1944FFICE CLUTCH OPERATING MECHANISM Clarence M. Eason', Waukesha, Wis.

Original application September 4, 1940, Serial No. 355,331. Divided andthis application August 7, 1941, Serial No. 405,745

rear or outer clutch plate i4 is formed integral 6 Claims.

The present invention relates to operating mechanism for frictionclutches used to control the transmission of power from a driving memherto a driven member. This application is a division of my prior PatentNo. 2,303,201, issued November 24, 1942, on Clutches."

One of the features of the invention resides in an improved constructionof toggle mechanism in the clutch operator.

Another feature of the invention resides in an improved toggle type ofclutch operator wherein centrifugal force is utilized to assist inmoving the clutch to one position, or to assist in holding the clutch inone position. When the shiftable clutch element and the clutch operatorelements are part of the driving assembly, this centrifugal force actioncan be utilized to assist in holding the clutch in its releasedposition.

Other features, objects and advantages of the invention will appear fromthe following detailed description of one preferred embodiment thereof.

In the accompanying drawings illustrating such embodiment:

Figure 1 is an axial sectional view taken approximately on the plane ofthe line l-i of Figure 2, showing my improved clutch embodied in a powertake-oil unit;

Figure 2 is a transverse sectional view taken approximately on the planeof the line 2-2 of Figure 1;

Figure 3 is a detail sectional view showing the clutch operatingmechanism in the clutch releasing position; and t Figure 4 is a detailsectional view on a larger scale of one of the adjustable mountingsleeves and cap screws which secure the flexible arms of the clutch discsegments to the flywheel, this view being taken approximately on theplane of the line 4-4 of Figure 2.

Referring to Figure 1, the clutch 8 is adapted to be secured to a rotarymember 9, which may be either a driving member or a driven member. Whenthe clutch is embodied in a power take-01f unit or is otherwise employedto control the transmission of power from an internal combustion engine,the rotary member 9 is preferably the flywheel of the engine, shown asbeing secured to a flange on the engine crank shaft by the bolts orscrews II. In such embodiment of the invention, the centrally disposedsegmental clutch disc i2 constitutes the driving element of the clutch.The driven portion of the clutch comprises the front and rear clutchplates l3 and i4, which are with a hub I! which is keyed to the frontendof the driven shaft it. The keyed relation of the hub IS on the shaftI8 is secured by a longitudinal key I! and also by a wedge fit of thehub l5 over the tapered portion ill of the shaft, such wedge fit beingeffected by a nut ill which screws over a threaded forward portion ofthe shaft. The front extremity 2! of the shaft has pilot mounting in apilot bearing 22 carried within a bore formed in the hub of the flywheel9.

The front or inner clutch plate iii of the driven pair i3, i4 is mountedfor sliding movement toadapted to be contracted together against thefront and rear sides of the driving disc i2. The

ward and away from the outer clutch plate i4. A plurality of compressionsprings 24 which are seated in pockets inthe opposing faces of theclutch plates at angularly spaced points around theclutch tend normallyto shift the inner clutch plate [3 to an inward, clutch-releasingposition. The clutch is engaged through the instrumentality of aplurality of pull pins 21 which are disposed at .angularly spaced pointsaround the clutch assembly. These pull pins slide in aligned 'guideapertures 28 and 29 formed in the clutch plates i3 and i4, respectively,and the inner end of each pull pin is formed with an enlarged head 3|which abuts against the inner end of a guide boss 32 projecting inwardlyfrom the clutch plate l3. The opposite or outer end of each pull pin isslotted transversely, as indicated at 33, and extending across said slotis a pivot pin34. Pivotally mounted in each slot 33 on the pin 34 is theapertured inner or forward end 36 of a toggle rocker 35. It will beunderstood that there is one of these toggle rockers 35 for each pullpin. The opposite or outer end of each toggle rocker has an aperturedeye 31 for receiving a knuckle pin 28. Intermediate these aperturedinner and outer ends, the toggle rocker is formed with an abutmentshoulder or fulcrum 39 which is adapted to have rocker bearingengagement against, an djustable abutment ring 4|. Said ring 4|, has aninternally threaded bore which screws over an adjusting thread 42 formedexternally on' a ring 43.

The ring 43 is held against rotation relatively to the driven clutchelements by an extension of the key [1. A plurality of worm wheel teeth45 are cut around the outer periphery of the abutment ring 4!, andmeshing with these teeth is a short adjusting worm 46 which is mountedon a short rotatable bearing shaft 41. The ends of the shaft 41 aremounted in two lugs 48 disposed relatively close together and projectingrearwardly from the driven clutch plate i4.

Formed in the periphery of the worm 40 are notches ll, into which snapsa detent spring I! that is secured to the driven clutch plate I by thescrew 33. .Theworm It is preferably secured to the shaft 1, and saidshaft has a polygonal head 40 for receiving a wrench by which the wormI. can be rotated. It will be evident that rotation of said worm willrevolve the abutment ring ll either forwardly or backwardly along thethread 42 o; the inner ring 43, thereby adjusting the axial on of theinner surface or said ring I, which the fulcrum shoulders 39 of thetoggle rockers bear. Convenient access to slots 03 for receiving thetoggle links 58. Pairs of radially projecting lugs or ears 04 extendoutwardly on each side of each slot I for receiving the transverse pivotpins 50 on which the toggle links 50 are mounted. Shifting motion isimparted to the clutch collar ll through a shifter fork I. which ismounted on a transverse operating shaft l1, and which is formed withnotched fork arms I. that embrace shifter lugs ll projecting laterally fom a shifter ring 12. This rin is a diametrically split ring, which hasits two halves bolted together over a radial flange II projecting fromthe shifter collar 0 I Figure 1 shows the position of the clutchoperating mechanism when the clutch is engaged, and Figure 3 shows theposition of the clutch operating mechanism when the clutch is released.In the operation of the mechanism, it will be evident that when theknuckle pivots 33 of the three or more toggle assemblies employed areoscillated in an inward direction toward the axis of the shaft it, suchmotion of the toggle rockers II creates a rocker motion about thefulcrum pivots 39, which causes the pivots 34 to pull the pull pins 21outwardly or rearwardly for engaging the clutch. Such inward oscillationof the knuckle pivots 30 is eifected by the shifting motion of theshifter collar CI in a direction toward the clutch assembly, as shown inFigure 1. To release the clutch, theshifter collar 61 is shiftedoutwardly in a direction away from the clutch assembly, as shown inFigure 3, with the result that the knuckle pivots a are permitted tooscillate outwardly in a direction away from the axis of the shaft ll.This takes the heavy rocking pressure of! the fulcrum points 39,permitting the pull pins 21 to shift inwardly or forwardly under theenergy of the release springs 21, in consequence of which the clutchassumes 9. released position.

It will be noted that the knuckle pins 30 can beengagement relatively tothe motion of the control pedal or control handle, it is only necessaryto open the spring cover II and to rotate the adjusting worm 46 forshifting the fulcrum ring ll backwardly or forwardly.

Referring to Figure 3. it will be seen that when the clutch operatingmechanism is in the clutch releasing position centrifugal force iscapable of acting very effectively on the mass of each toggle rocker IIand each to gle link 58. This centrifugal force, tends to swing thetoggle pivot or knuckle pin 30 of each toggle assembly in an outwarddirection, away from the shaft I6, thus tending to hold the clutch inits released position. This centrifugal force action aids in theoperation ofreleasing the clutch, irrespective of whether the rotarywheel member 9 or the shaft It is the driving member. In thoseembodiments of the invention wherein the shaft i8 is the drivingelement, and the clutch operating parts rotate constantly even when theclutch is disengaged, this centrifugal force action can also be utilizedto hold the clutch inits released position or to assist in holding it insuch position. The degree of the centrifugal force action can beproportioned by varying the mass of the toggle rockers, toggle links,and knuckle pivots.

The improved construction of the segmental clutch disc I! constitutesthe principal subject matter of my prior Patent No. 2,303,201, of whichthe present application is a division. This segmental disc i2 isillustrated and described in considerable detail in that application,and hence need not be described here. The above described clutchoperating mechanism can, of course, be used with various types offriction clutches having different forms of clutch discs. However, thereare certain features pertaining to the adjustable mounting of the springfingers of the segmental disc i2 that have cooperative relation to theadjustable relation of the clutch operating mechanism, and, accordingly,such adjustable mounting of the segmental disc II will now be described.It will be seen from Figure 2 that the disc I! is made up of a pluralityof segments ll, from which project the circumferentially extendingflexible arms 16, IS. The direction of rotation is represented as beingcounterclockwise (see arrow a in Figure 2), and when the disc I2 is thedriving element, the arms or fingers 16, I6 extend forwardly in thedirection of rotation, so that the driving torque always places thesearms under tension. In the preferred construction illustrated, the discis divided into four segments, and each segment is provided with twoarms or fingers, consisting of a leading arm I6 and a trailing arm 16',although this specific number of segments and number of arms isnot-essential. Secured to the front and rear sides of each disc segmentare the arcuate pieces of clutch lining material 11, the attachmentbeing effected by rivets or screws 18 in conventional manner.

Each segment I5 and its integral mounting arms l6, I6 is preferablystamped out of sheet metal stock, such as a suitable steel of theappropriate composition, temper, and gauge as to enable the mountingarms to flex the required amount for engaging and releasing the clutch,and for accommodating misalignment. preferred manner of punching thestampings, and the advantages of the particular shape of the springfingers as illustrated are fully disclosed in my prior Patent No.2,303,201, issued November 24, 1942, and also in my prior Patent No.2,259,- 461, issued October 21, 1941. The outer end of The each flexiblemounting finger or arm is apertured to receive a bolting thimble orbushing 8|. As shown in Figure 4, each bolting thimble or bushing isformed with a reduced inner end 8| which is passed through the aperturein the mounting finger and is then peened over to rivet the thimble tothe finger.

thimble 8| and through the sleeve 84 and taps into a threaded bore 85 ofsmaller diameter, extending coextensively from the inner end of thethreaded bore 85. The sleeve 84 is formed with an enlarged head portion84' which serves as an adjustable mounting stop for determining theposition of the apertured end of each mounting finger l6, 18. Theperiphery of the enlarged head 84' is of hexagonal formation to receivea wrench by which the sleeve 84 can be screwed inwardly or outwardly inthe bore 85 to adjust the fore and aft position of the abutment head84'. The stop sleeve 84 is rigidly held in any position to which it hasbeen adjusted upon the tightening of the cap screw 83, which exerts abinding force on the sleeve 84 for locking the latter in its adjustedposition. Figure 4.il1ustrates two positions of the disc segment I5, therear full-line position r representing thereleased position of theclutch disc. and the front dottedline position e representing theengaged position of the clutch disc. By adjusting the.mounting sleeves84 inwardly or outwardly, these positions r and e can be displacedforwardly or rearwardly with respect to the driven clutch discs i3 andi4, thereby adjusting for wear of the clutch linings H, or adjusting forthrow of the clutch control member. In the preferred constructionillustrated, the released position? of each segment coincides with thetransverse plane of the anchored outer ends of the fingers I6, 16,although,

if desired, these fingers might be given a set so that the releasedposition 1' of the segment would be displaced forwardly from thetransverse plane of the ends of the fingers as far as the engagedposition e would be displaced rearwardly from said plane. In theassembly of the clutch, all eight stop sleeves 84 are adjusted todispose their stop surfaces in the same transverse plane. This is easilyaccomplished by extending a gauge bar diametrically across the rear edge88 of the flywheel housing 89 (Figure l) this gauge bar having acalibrated stop against which the sleeves 84 are adjusted as the gaugebar is revolved around the edge of the flywheel housing. An arcuateopening 9| is formed in the upper part of the flywheel housing 89, thisopening being normally closed by any suitable cover 92. Access canreadily be gained to the cap screws 83 and stop sleeves 84 through thisopening 9i whenever it is desired to adjust the clutch for wear of theclutch linings.

While I have illustrated and described what I regard to be the preferredembodiment of my invention, nevertheless it will be understood that suchis merely exemplary, and that numerous modifications and rearrangementsmay be made therein without departing from the essence of the invention.

I claim:

1. In a clutchof the class described, the combination of a pair ofcooperating clutch elements, one of which is shiftable, pull pinsconnected to shift said shiftable clutch element, rocker memberspivotally connected at their forward ends to said pull pins, togglelinks pivotally connected to the other ends of said rocker members, ashiftable clutch operator operative to oscillate said toggle links,fulcrum projections on said rocker members intermediate the endsthereof, an internally threaded abutment ring against which said fulcrumprojections react, and an externally threaded mounting ring over whichsaid abutment ring threads, and along which it is adjustable, saidmounting ring trans mitting reaction pressure to the other of saidclutch elements.

2. In a clutch of the class described, the combination of a first clutchelement, a second clutch element comprising two relatively shiftableclutch members adapted to effect clutching engagement with said firstclutch element, toggle levers having pivotal mounting on one of saidrelatively shiftable clutch members for swinging movement in planesextending substantially radially of the clutch, a mounting ringassociated with the other of said relatively shiftable clutch members,an abutment ring screwing externally over said mounting ring for axialadjustment. fulcrum portions on said levers adapted to exert reactionpressure against said abutment ring at respective points spaced radiallyinwardly from the pivotal center of said toggle levers, a control sleeveshiftable axially of the clutch, toggle links having their outer endspivotally connected with said control sleeve, and knuckle pivotsconnecting the inner ends of said toggle links with said toggle levers,said knuckle pivots being mov-. able substantially into dead-centerrelation in approximately the same transverse plane as the outer pivotsof said links in the operation of ene sing the clutch.

3. In a clutch of the class described, the combination of a first clutchelement, a second clutch element comprising two relatively shiftableclutch members adapted to effect clutching engagement with said firstclutch element, pull pins connected with one of said relativelyshiftable clutch members, rocker levers having pivotal mounting on saidpull pins, an externally threaded mounting ring bearing against theother of said relatively shiftable clutch members, an internallythreaded abutment ring adapted to be screwed inwardly or outwardly alongsaid externally threaded mounting ring, fulcrum portions on said leversarranged for fulcrum engagement against said abutment ring at pointsrespectively spaced radially inwardly from said pull pins, a shiftersleeve shiftable axially of the clutch, toggle links, outer pivotsconnecting the outer ends of said toggle links with said shifter sleeve,and knuckle pivots connecting the inner ends of said toggle links withsaid levers, said knuckle pivots being movable into substantiallythesame transverse plane as said outer pivots in the operation ofengaging the clutch.

4. In a clutch of the class described, the combination of a first clutchelement, a second clutch element comprising inner and outer relativelyshiftable clutch members adapted to effect clutching engagement withsaid first clutch element, pull pins secured to said inner shiftableclutch member, a plurality of rocker members pivotally mounted on saidpulhpins for swinging-movement in planes extendirm-substantiallyradially of the clutch, fulcrum portions on said levers arranged to havefulcrum engagement against said outer shiftable clutch member at pointsspaced respectively radially inwardly of said pull pins, a controlsleeve shiftable axially of the clutch and rotating with said secondclutch element, toggle links associated with each rocker, outer pivot!pivotallyconnecting the outer ends of said toggle links with saidcontrol sleeve, and knuckle pivots pivotally connecting the inner endsof said toggle links with their respective rockers, said rockers, links,and knuckle pivots being arranged whereby said is adapted to havefulcrum engagement, and cooperating worm and worm wheel means oper-'ative to screw said abutment ring inwardly or ment, pull pins connectedwith said inner clutch knuckle pivots are movable substantially intodead center relation in the operation of engaging the clutch, andwherein centrifugal force acting on said rockers, links and knucklepivots tends to move said parts to clutch releasing position in theoperation of disengaging the clutch.

5. In a clutch, the combination of a first clutch element, a secondclutch element comprising inner and outer relatively shiftable clutchmem-; bers adapted to effect clutching engagement with said first clutchelement, a rocker having pivotal connection with said inner clutchmember, a control sleeve shiftable axially of the clutch, a motiontransmitting link having one end pivotally connected with said rockerand having its other end pivotally connected with said control sleeve,said rocker comprising a fulcrum portion, a threaded member associatedwith said outer clutch member, an abutment ring having threadedengagement with said threaded member and against which said fulcrumportion member and extending outwardly through said outer. clutchmember, rocker levers having pivotal mounting on said pull pins forswinging movement in planes extending substantially radially of theclutch, a controllable shifter sleeve shiftable axially of the clutch,toggle links having their outer ends pivotally connected with saidshifter sleeve and having their inner ends pivotally connected with saidrocker levers, fulcrum portions formed on said rocker levers inwardly ofsaid pull pins, an abutment ring against which said fulcrum portions areadapted to have fulcrum engagement, a threaded member associated

